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研究了烧碱氟硅酸钠法生产冰晶石并联产优质白炭黑的工艺条件,确定了烧碱分解氟硅酸钠生产白炭黑的影响因素。用低浓度的烧碱(循环生产过程中用母液)在一定条件下与氟硅酸钠反应,得到白炭黑软膏和氟化钠溶液。白炭黑软膏经洗涤干燥后得白炭黑产品;氟化钠溶液经二次过滤后打入储槽备合成用。将一定浓度的氢氧化钠溶液预热到100℃,加入计算量的氢氧化铝,搅拌反应直至溶液澄清,即得铝酸钠溶液。将氟化钠溶液和铝酸钠溶液按照一定的比例加入到合成槽,控制一定的合成温度,反应结束后过滤即得冰晶石产品。采用此方法合成的冰晶石与氨水氨解氟硅酸钠法生产的冰晶石相比流动性好、质量合格、适合电解铝启槽用,具有良好的市场前景,并且具有废水可以循环利用、环境污染少的特点。 相似文献
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由氟硅酸制氟化钠和白炭黑的工艺研究 总被引:15,自引:3,他引:12
氟硅酸是湿法生产磷肥的副产品,大型磷复肥装置副产的产品多用于生产氟化铝,过磷酸钙装置副产的产品大多生产氟硅酸钠,经济效益欠佳。论述了由氟硅酸和纯碱制氟化钠和白炭黑的原理和工艺条件,研究了各种因素对产品质量和产品收率的影响,指出对ω(H2SiF6)较低的氟硅酸采取提高反应温度、延长反应时间,可制得质量符合国家标准要求的氟化钠和白炭黑,并对该工艺的工业应用前景和经济效益进行了探讨。 相似文献
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氟化钠的工业生产有多种工艺路线,产品成本普遍偏高。提出一种以生产水合肼副产的碱渣代替纯碱与磷肥工业副产的氟硅酸钠反应生产氟化钠的生产工艺。该工艺成本低廉,工艺切实可行。主要工艺条件:氟硅酸钠与碳酸钠物质的量比1.0:(2.08-2.16),反应温度85~95℃,反应时间100~120min,pH=8-9;母液用硫酸酸化,温度85℃,pH=5~6。通过生产证明,此工艺生产的氟化钠产品和水合二氧化硅副产品的质量均达到或超过国家标准一级品标准,而其生产成本比其他工艺生产成本低。 相似文献
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介绍了采用氟硅酸钠和碳酸钠在一定温度下进行复分解反应制备氟化钠同时副产白炭黑的工艺技术。以年产3 000 t氟化钠同时副产450 t白炭黑项目为例,以外购的氟硅酸钠为原料,介绍了工艺技术和生产操作要点。项目实际生产运行情况表明,生产运行期间各项经济技术指标均达到了设计要求,氟化钠产品质量达到YS/T 517-2009《氟化钠》各项指标要求,白炭黑产品质量达到HG/T 3061-2009《橡胶配合剂沉淀水合二氧化硅》各项指标要求。如果将该项目与磷肥企业配套建设,可以有效利用磷肥企业的附属产品氟硅酸钠,进而生产高附加值的氟化钠产品,同时副产白炭黑产品,延伸磷肥企业附属产品的产业链。 相似文献
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尿素法生产水合肼副产大量盐碱渣,由于盐碱渣中杂质较多一直未得到有效利用。介绍了一种合理利用水合肼副产盐碱渣的方法,即:将盐碱渣进行盐碱洗涤分离,得到含碱的洗涤母液和固体氯化钠,利用洗涤母液中的碳酸钠和氢氧化钠生产氟化钠。该工艺既回收了盐碱渣中的氯化钠和碱、副产了白炭黑,同时还解决了环境污染问题。研究了各种因素对氟化钠产品质量和收率的影响,得到较佳工艺条件:1)加料方式为先将氟硅酸钠制成悬浊液,加热至60 ℃左右,再向其中慢慢滴加洗涤母液,滴加速度控制在15~20 L/min;2)洗涤母液中碳酸钠质量分数控制在20%~25%,反应温度控制在85~90 ℃;3)母液中杂质氯化钠质量分数控制在15%~20%。 相似文献
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以不同浓度的硅酸钠、碳酸钠及二者混合物作稳定剂,研究它们对有效氯含量为0.5%(质量分数,下同)的次氯酸钠溶液化学稳定性的影响。测定稳定化处理后次氯酸钠溶液中有效氯的含量,结果表明:54 ℃下恒温密闭静置14 d后,加入硅酸钠、碳酸钠以及二者混合物作稳定剂的次氯酸钠溶液的有效氯,最高分别可保留初始浓度的88.16%、86.81%和92.85%;而不加任何稳定剂的次氯酸钠溶液在同样条件下其有效氯含量仅仅可保留初始浓度的76.58%。实验结果表明,硅酸钠和碳酸钠的混合物可以作为次氯酸钠溶液的良好稳定剂。 相似文献
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分析以氯化钠为原料生产氟硅酸钠存在的问题,提出用硫酸钠代替氯化钠生产氟硅酸钠,并从工艺、设备、仪表和土建等方面介绍装置技改情况,以及改造后的经济效益。 相似文献
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Hydrophilic sodium carboxymethylcellulose (NaCMC) matrices were chemically modified into hydrophobic gels by ionotropic crosslinking with cupric or ferric ion under ambient temperature and pH. Insoluble matrices were also prepared using an interactive polymer gelatin in combination with NaCMC. These matrices underwent erosion at the crosslinks, followed by matrix erosion when released in water. The matrix erosion in water was influenced by the gelling agent, initial crosslinker density, and gelatin content in the insolubilized matrices. The apparent diffusion coefficients of fenthion ranged from 7.2 × 10?9 to 175.6 × 10?9 cm2/sec, with matrices prepared under different conditions. These erosion-controlled matrices can be used for the controlled release of various biologically active agents. © 1993 John Wiley & Sons, Inc. 相似文献
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Diffusion coefficients of sodium chloride, sodium nitrate and oxygen were determined for heterotrophic biofilms. The biofilms were cultivated under different hydrodynamic and substrate loading conditions in tubular reactors resulting in biofilm densities between 3 and dry mass. Quantifying solute diffusion in the biofilm for these biofilms allowed to specifically evaluate the influence of biofilm density on diffusion while keeping other factors such as the type of substrate, the inoculum, and the reactor type constant. Two methods were used to measure diffusion coefficients. The two-chamber method was used to quantify the diffusion of sodium chloride and sodium nitrate. The diffusion coefficients for oxygen were measured based on oxygen concentration profiles in the biofilm measured using microelectrodes. The ratio between the diffusion coefficient in biofilm and water (fD=DF/DW) was found to be lower than 1 in the majority of experiments. A clear correlation between fD and biofilm density was found where fD decreased with increasing biofilm density. For mean biofilm densities in the range of 10- can be approximated between 0.5 and 1. For larger densities of 20 or can be approximated as 0.8 or 0.4, respectively. For densities higher than is below 0.6. Advective transport mechanisms that would have resulted in fD>1 can be neglected in the biofilms cultivated. 相似文献
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针对以氯化钠为原料生产氟硅酸钠所带来的污水难以回收利用问题,改用硫酸钠为原料生产氟硅酸钠。介绍了其生产流程及生产控制指标;通过两个阶段的生产试验,确定了氟硅酸钠生产污水用于磷酸过滤洗水改造方案。改造后保证了生产工艺的正常及氟硅酸钠产品质量的稳定,实现了污水的综合利用。 相似文献
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G. C. Schweiker 《Journal of the American Oil Chemists' Society》1978,55(1):36-40
A highlight summary of the chemistry and commercial manufacturing processes involved in making sodium silicates and sodium
aluminosilicates (zeolites) is presented. Some relative and current raw material costs and energy needs, and overall qualitative
economic comparisons of the various processes are discussed. Estimated world market consumption of both silicates and zeolites,
by geographical areas and by major applications, is reviewed. Market volume projections into the near future are ventured
on a worldwide basis, indicating substantial growth. Capacity to supply silicates in North America to 1983 is presently in
place, but most other geographical areas of the world will require increased manufacturing capabilities to keep in balance
with the projected market growth. It is suggested that zeolite production in the world will increase over fivefold by 1981,
due principally to the expected rapid growth of its use in detergent formulations. 相似文献